This binary opposition of reason vs emotion which has persisted throughout the ages has given rise to a plethora of faux dichotomies such as the following:
Rational mind vs emotional mind, prefrontal cortex vs limbic system, head vs heart, flesh vs spirit and so on.
Lisa Feldman Barrett author of the ground breaking "How Emotions are Made" insists there is no such thing as a purely rational actor. Every thought and every decision is infused with feeling and every emotion is infused with thought.
The myth of the autonomous rational mind arises from the notion of a triune brain; what Feldman alludes to as an "illusory arrangement of layers". The "alleged" limbic system is part of this arrangement. The idea perpetuated here is that the limbic system is the emotional center while the prefrontal cortex is the executive seat of rationality.
“Mapping emotion onto just the middle part of the brain, and reason and logic onto the cortex, is just plain silly,” says neuroscientist Barbara L. Finlay, editor of the journal Behavior and Brain Sciences. “All brain divisions are present in all vertebrates.”